[flood] postrm script doesn't seem to work correctly

[Zriel88]

zriel@dedi-par-129709:~/flood$ docker container exec -it seedbox_rtorrent-flood_1 /bin/sh
/ #
/ #
/ # ls
bin       etc       home      mnt       run       sys       var
data      filebot   lib       proc      sbin      tmp
dev       flood-db  media     root      srv       usr
/ # /usr/bin/postrm
/ # ps -ef
PID   USER     TIME   COMMAND
    1 1000       0:00 /bin/s6-svscan /etc/s6.d
   17 1000       0:00 s6-supervise rtorrent
   18 1000       0:00 s6-supervise flood
   19 1000       0:28 {rtorrent main} rtorrent
   20 1000       0:35 node /usr/flood/server/bin/www
  217 root       0:00 /bin/sh
  222 root       0:00 /bin/sh
  231 root       0:00 /bin/sh
  238 root       0:00 {postrm} /bin/sh /usr/bin/postrm
  239 root       0:00 sleep 10
  240 root       0:00 ps -ef
/ # /usr/bin/postrm: line 11: file: not found
/ # /usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
/usr/bin/postrm: line 11: file: not found
find: unrecognized: -empty
BusyBox v1.26.2 (2017-08-03 13:08:12 GMT) multi-call binary.

Usage: find [-HL] [PATH]... [OPTIONS] [ACTIONS]

Search for files and perform actions on them.
First failed action stops processing of current file.
Defaults: PATH is current directory, action is '-print'

        -L,-follow      Follow symlinks
        -H              ...on command line only
        -xdev           Don't descend directories on other filesystems
        -maxdepth N     Descend at most N levels. -maxdepth 0 applies
                        actions to command line arguments only
        -mindepth N     Don't act on first N levels
        -depth          Act on directory *after* traversing it

Actions:
        ( ACTIONS )     Group actions for -o / -a
        ! ACT           Invert ACT's success/failure
        ACT1 [-a] ACT2  If ACT1 fails, stop, else do ACT2
        ACT1 -o ACT2    If ACT1 succeeds, stop, else do ACT2
                        Note: -a has higher priority than -o
        -name PATTERN   Match file name (w/o directory name) to PATTERN
        -iname PATTERN  Case insensitive -name
        -path PATTERN   Match path to PATTERN
        -ipath PATTERN  Case insensitive -path
        -regex PATTERN  Match path to regex PATTERN
        -type X         File type is X (one of: f,d,l,b,c,...)
        -perm MASK      At least one mask bit (+MASK), all bits (-MASK),
                        or exactly MASK bits are set in file's mode
        -mtime DAYS     mtime is greater than (+N), less than (-N),
                        or exactly N days in the past
        -mmin MINS      mtime is greater than (+N), less than (-N),
                        or exactly N minutes in the past
        -newer FILE     mtime is more recent than FILE's
        -inum N         File has inode number N
        -user NAME/ID   File is owned by given user
        -group NAME/ID  File is owned by given group
        -size N[bck]    File size is N (c:bytes,k:kbytes,b:512 bytes(def.))
                        +/-N: file size is bigger/smaller than N
        -links N        Number of links is greater than (+N), less than (-N),
                        or exactly N
        -prune          If current file is directory, don't descend into it
If none of the following actions is specified, -print is assumed
        -print          Print file name
        -print0         Print file name, NUL terminated
        -exec CMD ARG ; Run CMD with all instances of {} replaced by
                        file name. Fails if CMD exits with nonzero
        -exec CMD ARG + Run CMD with {} replaced by list of file names
        -delete         Delete current file/directory. Turns on -depth option